<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<script src="https://cdn.bootcdn.net/ajax/libs/jquery/3.6.0/jquery.js"></script>
<body>
    <textarea name="" id="" cols="30" rows="10"></textarea>
    <input type="text" id="int">
    <button id="save">提交</button>
</body>
<script>
    $('#int').css('width','200px').css('height','40px').css('font-size','20px')
    $('#save').css('width','100px').css('height','40px')
    var str = ''
    var i = 0
    $('#save').click(function(){
        var a = $('#int').val()
        str += `${++i}:${a}\n`
        $('textarea').text(str)
    })

    
</script>
</html>